Responder vs Nessus Essentials: Which Malware Analysis tool is Best in 2025?

Responder is a robust, open-source tool designed for network penetration testing, specializing in Link-Local Multicast Name Resolution (LLMNR), NetBIOS Name Service (NBT-NS), and Multicast DNS (mDNS) poisoning. Pre-installed on Kali Linux, Responder enables cybersecurity professionals and ethical hackers to intercept network authentication requests, capture NTLM hashes, and perform man-in-the-middle (MITM) attacks by mimicking legitimate servers. Developed by Laurent Gaffié, it targets Windows environments where LLMNR and NBT-NS are enabled by default, making it a powerful tool for credential harvesting and network security assessments.

Nessus Essentials is a free vulnerability scanning tool from Tenable, Inc., designed for students, educators, and small-scale users to perform high-speed, in-depth vulnerability assessments on up to 16 IP addresses per scanner. Part of the renowned Nessus family, it leverages Tenable’s extensive plugin database (over 252,000 plugins) to identify security weaknesses, software flaws, and misconfigurations across networks, devices, and applications. Introduced as a rebranded Nessus Home in 2019, it’s ideal for personal home networks, educational purposes, or small businesses starting in cybersecurity. Nessus Essentials runs on Windows, Linux, macOS, and platforms like Raspberry Pi, offering a web-based interface and NASL scripting for custom plugins.